Question

Constants | Periodic Table
Ammonia, NH3(g), and hydrogen chloride, HCl(g), react to form solid ammonium chloride, NH4Cl(s):
NH3(g)+HCl(g)→NH4Cl(s)
Two 3.00 L flasks at 35.0 ∘C are connected by a stopcock, as shown in the drawing . One flask contains 6.00gNH3(g), and the other contains 4.80 g HCl(g). When the stopcock is opened, the gases react until one is completely consumed.

Part A

Which gas will remain in the system after the reaction is complete?

Which gas will remain in the system after the reaction is complete?

NH3
HCl

Part B

What will be the final pressure of the system after the reaction is complete? (Neglect the volume of the ammonium chloride formed.)

Pfinal =     atm  

Part C

What mass of ammonium chloride will be formed?

mNH4Cl =    g  

Answer 1

The balanced reaction is

NH3(g) + HCl(g) ------------ NH4Cl(s)

Number of moles of NH3 = Mass/molar mass = 6.00/17.031 = 0.3522 moles

Number of moles of HCl = Mass/molar mass = 4.80/36.45 = 0.1316 moles

Since they react in 1:1 ratio, hence HCl is the limiting reagent

The gas will remain will be NH3

Part b

moles of NH3 left = 0.3522 - 0.1316 = 0.2206 moles

Final volume = 3.00L + 3.00L = 6.00 L

Using the ideal gas equation

PV = nRT

P * 6 = 0.2206 * 0.0821 * (273.15+35)

P = 0.930 atm

Part C

Number of moles of NH4Cl formed = 0.1316 moles

Mass of NH4Cl formed = number of moles * molar mass = 0.1316 mol * 53.49 gm/mol = 7.039 grams